1. Field of the Invention
This invention relates to a method of cutting, or scanning and cutting full-sized, substantially tree-length "stems" by means of an automatic stem cutting apparatus which is designed to analyze and rapidly process the stems into segments of optimum character. The apparatus is characterized in a preferred automated mode, by a scanner for determining the physical characteristics of incoming stems in sequence, a computer for receiving the scanned information, a programmable logic controller for receiving data from the computer and executing the computer commands to orchestrate operation of the respective apparatus functions, a diverter for diverting the stems from a preselected path, such as a conveyor, a loading apparatus for sequentially receiving the stems and loading the stems one-by-one onto several saw carriages or modules , all but one of which are prepositioned for optimum cutting of each stem by means of carriage positioning cylinders connected to the programmable logic controller, rollers for receiving the stems, clamps located on the saw carriages for stabilizing the stems prior to cutting, circular saws provided in the saw carriages for cutting the stems in concert at the optimum locations determined by the computer and an ejection mechanism in each saw carriage for ejecting the cut segments onto a conveyor for further processing.
One of the problems associated with "bucking" or handling tree-length logs, or "stems" of various size and shape with an infinite pattern of sweep, knots, depressions, twists and other defects and cutting the stems into properly sized logs, poles and other segments for further processing, is that of determining the optimum cuts for each stem in order to provide an optimum stem value from the segments. Various scanning devices and mechanical means for achieving this purpose have been developed in combination with log bucking saws, slasher decks, debarkers and like equipment for achieving the purpose. A primary problem associated with these systems is the complexity of the equipment required and the accompanying slow feed and processing time required to initially determine the optimum cuts in the stem and subsequently effect these cuts to produce segments of optimum length. Added to the problem of slow processing and handling time is that of the considerable down-time required for maintenance purposes, which maintenance down-time is a function of the complexity of the equipment used to process the stems into logs and other segments.
It is therefore an object of this invention to provide an improved, simple and efficient stem evaluation and processing technique and apparatus which is designed to manually, semiautomatically or automatically evaluate the physical characteristics of each incoming stem in sequence and cut the stem into logs, poles and other segments of optimum length for further processing.
Another object of this invention is to provide an automatic stem cutting apparatus which is characterized by an optical scanning device for analyzing the physical characteristics of incoming stems in sequence; a computer receiving the scanned data; a programmable logic controller for controlling the various machine functions; a loading device for receiving each stem and momentarily locating the stem in a holding position; multiple, separately linearly-adjustable saw carriages, each fitted with an encoder and a carriage positioning cylinder electrically connected to the programmable logic controller for adjusting the carriages with respect to the next stem, and further including stem rollers, stem clamping devices and a circular saw for receiving the stem from the loading apparatus, clamping it in place and cutting the stem into segments of optimum length, the carriages also having ejection devices for ejecting the segments from the saw carriages and delivering the segments to a conveyor for transport to further processing.
A still further object of this invention is to provide a new and improved automatic stem cutting apparatus which is computer-controlled and includes an optical scanner for determining the physical characteristics of the incoming stems in sequence; a computer electrically coupled to the scanner; a programmable logic controller electrically connected to the computer and to various positioning cylinders in the apparatus, including a carriage positioning cylinder provided in each one of several linearly-adjustable saw carriages mounted on rails and fitted with encoders electrically coupled to the programmable logic controller, to facilitate automatically positioning the saws adjacent to a loading platform. The loading platform receives the stems one-by-one and is fitted with a loading apparatus for sequentially loading the stems onto the carriage, where the stems are received by rollers, clamped and cut into logs, poles and other segments of optimum length. Ejector mechanisms are provided on each saw carriage for ejecting the cut segments onto a conveyor for transport to further processing.
Yet another object of the invention is to provide a method of "bucking" or cutting stems into segments of optimum length, which method includes the steps of determining the physical characteristics of the stems, positioning multiple saw carriages to receive, clamp and cut the stems, off-loading the stems onto one or more stem loaders, loading the stems from the stem loaders onto the saw carriages, clamping the stems in transverse cutting configuration, cutting the stems into segments of optimum length and ejecting the segments from the saw carriages for transport to further processing.